1. Field of the Invention
The present invention relates to a multi-type air-conditioning apparatus including a plurality of indoor units.
2. Description of the Related Art
A multi-type air-conditioning apparatus is known which includes one outdoor unit and plurality of indoor units to provide a heat pump type refrigerating apparatus.
The air-conditioning apparatus can conveniently cool or heat a plurality of rooms at a time in a house or a building.
In a building having a computer room or a building having a perimeter zone or an interior zone, however, upon a request of a cooling mode from one location a request or requests for a heating mode are sometimes made from an other location or locations.
In such a situation, one of the cooling and heating modes cannot be performed in preference to the other.
For this reason, even if a better circumstance is obtained at that location, an occupant or occupants at the other location or locations feel uncomfortable or an apparatus, such as a computer, may sometimes fail.
Such inconvenience is often experienced in the spring and autumn times not only in the building but also a common house having a plurality of rooms.
An air-conditioning apparatus has emerged on the market which can simultaneously perform a cooling and a heating mode in a plurality of indoor units.
For example, Published Unexamined Japanese Patent Application 61-45145 discloses an air-conditioning apparatus including one outdoor unit having a compressor and outdoor heat exchanger and a plurality of indoor units connected to the outdoor unit and having an indoor heat exchanger each and adapted to, when at least one of the plurality of indoor units is operated in a cooling mode. operate at least one of the remaining indoor units in a heating mode.
Published Unexamined Japanese Patent Application 64-57061 discloses an air-conditioning apparatus including one outdoor unit having a compressor and outdoor heat exchanger and a plurality of indoor units connected to the outdoor unit via a multi-control unit and having an indoor heat exchanger each and adapted to, when at least one of the plurality of indoor units is operated in a cooling mode, operate at least one of the remaining indoor units in a heating mode.
U.S. Pat. No. 4,878,357 discloses an air-conditioning apparatus including one outdoor unit having a compressor and outdoor heat exchanger and a plurality of indoor units having an indoor heat exchanger each and adapted to, when at least one of the plurality of indoor units is operated in a cooling mode, operate at least one of the remaining indoor units in a heating mode, in which case the outdoor heat exchanger is divided into a plurality of sections.
However, these conventional apparatuses simply describe a basic flow of a refrigerant for performing a simultaneous cooling/heating operation in the plurality of indoor units and no effective countermeasure is made against the generation of any refrigerant noise and vibration as caused by a change in the number of operated ones of the indoor units.
That is, the aforementioned air-conditioning apparatuses generate such refrigerant noise and vibration upon a change in the number of operated indoor units, disturbing an occupant and occupants around the unit due to the generation of discordant noises.